The field of the disclosure relates generally to wind turbines and, more particularly, to methods and systems for determining bond width on a wind turbine blade.
Turbine blades are the primary elements of wind turbines for converting wind energy into electrical energy. Known turbine blades have an airfoil cross-sectional profile such that, as air flows over the blade during operation, a pressure difference between a pressure side and a suction side of the blade is created, generating a lift force on the blade. The lift force generates torque on the main rotor shaft, that is coupled to a generator for producing electricity.
At least some known turbine blades consist of an upper (suction side) shell and a lower (pressure side) shell that are bonded together at joints along the trailing and leading edges of the blade. Generally, the edge joints are formed by applying a suitable bonding paste or compound along the edge joint such that a minimum designed bond width id defined between the shell members. To ensure the turbine blades will satisfy performance and lifecycle requirements, the width and the overall integrity of these adhesive bonds is frequently verified.
At least some known methods of inspecting the adhesive bond joints include visual inspection and/or non-destructive imaging inspection techniques such as ultrasonic testing and microwave inspection. However, at least some known turbine blade materials may be difficult to penetrate via ultrasound. Certain areas of the turbine blade may be obscured from ultrasonic testing because of the use of foam, balsa, or other types of core materials that do not allow ultrasonic frequencies to be easily transmitted therethrough. In addition, at least some known microwave inspection techniques may be limited by a potential for exposure to radiation.